Currently, all electrical accessories for flush mounting are similar in structure.
Such an electrical accessory thus comprises: an electrical box that is open at the front and that is for fitting through an opening formed in the hollow partition; an accessory support in the form of a frame for fitting on the open front face of the electrical box; an accessory mechanism (e.g. a power-outlet or a switch mechanism) for blocking in the opening defined by the accessory support; and a finishing plate for fastening on the accessory support so that it hides said accessory support and so that it borders the accessory mechanism in attractive manner.
In particular, the accessory mechanism comprises an insulating block that houses connection terminals for connecting to the local electricity network, and that is closed at the front by a piece of trim that is user-accessible (a toggle or push button for an on/off switch or two-way switch, a connection well for a power outlet, . . . ).
It should be understood that the insulating block, suitable for engaging in the opening of the accessory support, presents a width that is small compared to the diameter of the electrical box, and this restricts the number of functions that the accessory mechanism may have.
In order to install such an electrical accessory in an opening formed in a hollow partition, it is likewise necessary to implement a large number of operations.
It is thus necessary to pull at least one cable-routing conduit through the opening formed in the hollow partition, to engage the end of each conduit in the electrical box, to fasten the electrical box in the opening formed in the hollow partition, pushing each conduit back into the hollow partition, to screw-fasten the accessory support on the electrical box, to connect the electric wires coming from each conduit to the terminals of the accessory mechanism, to block the accessory mechanism in the accessory support, and to fit the finishing plate on the accessory support.
These operations are time-consuming and tricky to perform.
The number of elements necessary for fastening the electrical accessory on the hollow partition is also large, and this is costly.
Document U.S. Pat. No. 3,879,101 discloses an accessory mechanism that is made of two parts, which mechanism comprises a rear casing that is designed to be fastened inside an electrical box, and a front casing that is designed to be mounted on the rear casing or removed from the rear casing.
The rear casing includes side terminals for connecting to electric wires coming from the local electricity network. It also includes two arms that are adapted to be fastened by screw-fastening through two holes provided in the electrical box.
The front casing includes two rear terminals that are adapted to plug into sockets provided in the front of the rear casing. It also includes two flanges, each perforated with an opening for screw-fastening the front casing through two openings provided in the rear casing.
This accessory mechanism does not solve the above-mentioned problem of size. Furthermore, it turns out to be difficult to install in a wall, in particular because it requires the use of a large number of components and screws. In addition, once assembled, there remains a gap between the edge of the front casing and the edge of the electrical box, and elements can become engaged in the gap to the detriment of the electrical safety of the assembly. Finally, the arms of the rear casing that make it possible to fasten the rear casing on the electrical box by screw-fastening, form extra thickness projecting from the front of the electrical box. This extra thickness goes against the object generally desired in the design of an electrical accessory for flush mounting in a wall, namely to design electrical accessories that project little from the front of the wall.